The present invention relates to a storage system, and more particularly to an automatic controlled multi-level storage system controlled by a programmed computer for the compact storage and rapid retrieval of storage items, such as motor vehicles, cargo containers, etc.
Because the cost of land in downtown areas and industrial areas is expensive, the effective utilization of space for storage should be maximized. Various multi-level storage systems have been proposed to minimize the amount of land for storing more automobiles, cargo containers, and many other items of cargo. In U.S. Pat. No. 4,768,914, there is disclosed a storage system for moving and storing cargo such as automobiles, cargo containers and the like. The storage system comprises an array of contiguous storage spaces on each level within a structure, each storage space being provided with a first means for supporting and moving a storage platform back and forth in longitudinal direction, and a second means for supporting and moving a storage platform from the side in a transverse direction, and elevator means for raising and lowering any of a plurality of storage platforms and cargo thereon to a desired level. However, this storage system is still not satisfactory in function. Because a number of heavy powered jacks are used and installed in the storage space below the first means, second means and elevator means, the installation process of the storage system is complicated, and the building structure must be reinforced to support the heavy load. The storage system further comprises shift means for selectively bringing one of the supporting and moving means into and out of operative engagement and support of corresponding pair of guide rails, so that one of the first and second supporting and moving means is in supportive contact with one of a plurality of storage platforms at any time when the platform occupies the corresponding storage space. The arrangement cannot absolutely eliminate the problem of engagement errors. Any tiny engagement error may cause vibration of a storage platform as it is moved from one storage space to another. The storage system further comprises platform storage means for accommodating storage platforms when they are not positioned in the storage space. The platform storage means comprises at least one storage well wherein the storage platforms may be placed in a vertical stack, means for raising and lowering the stack so that the topmost of stored storage platforms may be horizontally aligned with at least one level of the building structure, and means for removing the topmost platform from and returning any of storage platform to the stack in the at least one storage well. Because a tray hoist system and hydraulic cylinders are used as means for moving and storing storage platforms in the storage well, effective operation can be achieved only when storage platforms are precisely positioned. Any positioning error of storage platforms (due to the aforesaid engagement errors) may cause a catching failure. Further, because storage platforms are to be placed in a vertical stack, a great friction resistance will be produced and transmitted to the hydraulic cylinders when one storage platform is placed on or retrieved from another, thereby shortening the service life of the hydraulic cylinders.